MOLEEN PEAK. 601 



StreptorhyncJms crassus. 

 Orthis carbonaria. 



Eumetria punctulifera. 



This limestone series is conformably underlaid along the north base by a 

 series of quartzites and quartzitic conglomerates, carrying quartz and jasper 

 pebbles, from the size of a filbert to that of an eg^^ resembling those exposed in 

 Moleen Canon. Their bedding is broad and heavy, and the colors green, 

 yellow, and purple ; the general texture of the quartzite is very coarse, 

 closely resembling that of the Weber group. East of the canon of the South 

 Fork, the same limestones continue for about 8 miles on their strike, showing 

 a little Weber Quartzite on their north base near the canon, and consider- 

 able development of quartzitic strata high up on the series along the south- 

 east foot-hills. 



To the east of the Elko Range, the whole broad valley of the South 

 Fork is a plain of horizontally-bedded Humboldt Pliocene, through which 

 the narrow stream-beds are eroded. It is very difficult to get at the 

 character of the beds, the best exposures being along the branches of the 

 South Fork, where a couple of hundred feet of fine, siliceous, marly beds 

 with occasional clay-seams occur. At the angle formed by Dixie Creek 

 with the South Fork of the Humboldt, just southeast of Moleen Peak, there 

 crops through the Tertiary plain a northeast ridge, or rather a low table of 

 Carboniferous limestone of a prevailing light-blue color, banded with yellow 

 and buff beds, like the ne^'ghboring limestones of Moleen Peak. This iso- 

 lated outcrop is very much broken up, but possesses a general dip to the 

 eastward, and is, without doubt, a fragment dislocated from the Moleen 

 Peak mass. 



Opposite the town of Elko, the limestones break off suddenly, and a 

 low depression in the Elko Range is filled with beds of the Humboldt 

 Pliocene, which, on the eastern side, have been eroded away, exposing 

 upturned strata of the Green River Eocene, the northwestern foot-hills flank- 

 ing the pass on either side being made up of flows of red porphyritic rhyo- 

 lite. The beds of the Green River Eocene as exposed here have a strike 

 due north, and* dip 35° to the eastward. They resemble closely those 



